<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    
    <script src="https://cdn.socket.io/4.0.1/socket.io.min.js" integrity="sha384-LzhRnpGmQP+lOvWruF/lgkcqD+WDVt9fU3H4BWmwP5u5LTmkUGafMcpZKNObVMLU" crossorigin="anonymous"></script>

    <script>
    var socket = io();
    </script>
</body>
</html>